Querying AD with Powershell – First Shakey Steps

As I’m sure you know, I tend to jump in to learning stuff by trying out real world examples. This accelerates the learning process as there’s a desired outcome but it does make my understanding of the foundations a bit ropey. Never mind, let’s dive right in! 😀

In order to be able to query Active Directory with Powershell, we need to first load up the module that allows Powershell to understand what the heck you’re asking for. That’s the easy bit:

Import-Module ActiveDirectory

OK, so now we’ve got the ability to ask AD questions, let’s ask it for some basic info. Imagine my login is the truly imaginative USER1 in AD. To run a dead simple query, I could just type:

Get-ADUser user1

What that will do is bring up a very little list of selected fields Microsoft thought you might want. Bless ’em, they’re trying to be as helpful as they can. If you want the whole truckload, you can ask it for them:

Get-ADUser user1 -properties *

That’s going to give you the usual suspects of AD users’ properties, so you now have your SID, cn, samaccountname, department, etc. being displayed. If you don’t want all of it and you don’t just want the few provided by the normal output of Get-ADUser then we need to start doing the cool stuff in Powershell. You can pipe one command’s output into the input of the next, stay with me here it’ll make sense. By using the “|” operator you are saying that you want the output of command A fed into command B. So… command A | command B will process command A (in our case a query on a single AD user returning all of the properties for it in to command B (which we’re about to make a Select statement).

Select isn’t implemented the same way as you see in SQL, it’s a soft of cousin but the principles are the same. Here we go:

This one’s now a lot more friendly to you as it’s pulling back only the bits you want.
OK, moving on from querying a single user what if you wanted to get the username of everyone in the Marketing department? Well, as long as you’re using the fields in AD correctly for your users, you can use the Filter command.

The filter command is the first time you’ll see the curly bracket in this little post but it sure as heck won’t be the last! Curly brackets are implemented in a very similar way to C and C++ if you’re familiar with those two powerhouses. Imagine them as the boundaries for your complex little bit of code. Again, it makes more sense if you just see it in action:

Not too impressive yet but try to remember the output of this can be used with the “|” character to output the list that you just output to the screen as the input for a command to set up a new security group for example. Now we’ve turned what could take a while for a Marketing department of say, 25 people into a short set of commands that take no time at all to achieve what you were looking to do. That’s the Power part of the name Powershell!

I’ll be back soon to add to the querying side but for now, enjoy your weekend and I’ll talk to you soon.